Download Paper clip Activity

Name:____________________ Date:________________
Chemistry
1-6 Explore
Paper Clip Patterns
In this activity you will explore why measurements involve a degree of uncertainty.
Materials (per student)
Paper Clip
Procedure
1. Measure the length of a paper clip on each ruler pictured below. The measurements will
not be identical. Write your answers in the space provided.
length of paper clip
______-cm
length of paper clip
______-cm
length of paper clip
______-cm
Questions
1. Were all of your measurements identical? Explain.
2. Which measurement required the greatest amount of estimation? Explain.
3. How do your measurements indicate this difference in the degree of estimation needed?
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Name:____________________ Date:________________
Chemistry
1-6 Practice Problems
Identify the number of significant digits in each of the following measurements. Write the
number in the space provided.
1. 520-mL ______________
5. 10.002-ns ______________
2. 0.0102-ms ______________
6. 0.451-Pa ______________
3. 0.230-kg ______________
7. 0.001-cm ______________
4. 25,600-L ______________
Perform the following calculations and round off the answer to the correct number of
significant digits.
8. 0.3287-g x 45.2-g =?
13. 0.258-mL + 0.36105-mL =?
9. 125.5-kg + 52.68-kg + 2.1-kg =?
14. (1250-cal - (234.207-cal ÷ 52.69-cal)) =?
10.52.8 Pa + 3.0025 Pa = ?
253.4 Pa
15. 78.26 L - 89.50 L = ?
678.2-L+9511-L
11. (0.12-g + 5.16-g) x (45.56-g - 93.0-g) = ?
12. 68.32-ns + (-1.001-ns) + (-0.00367-ns) + (-678.1-ns) = ?
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Name:____________________ Date:________________
Chemistry
1-6 Practice Problems (continued)
Express each of the following numbers in scientific notation.
16. 8960
19. 36,000,000 ______________
17. 0.00023 ______________
20. 0.0000000253 ______________
18. 86,000 ______________
Check the following equalities for errors. If an answer is correct, write "correct" in the
space provided. If an answer is incorrect, rewrite it to make it correct.
21. 45,630,000 = 4.563 x 107 ____________________
22. 0.000253 = 2.53 x 10-3 ____________________
23. 680,500,000 = 68.05 x 108 ____________________
Solve each of the following problems as directed. Show all your work.
24. An unknown liquid has a mass of
30.6-g and a volume of 52.3 mL.
What is the density of the liquid?
27. The density of ice is 0.917-g/cm3.
How much volume does 52.3-g of ice
occupy?
25. Iron has a density of 7.86-g/cm3.
Could a block of metal with a mass of
18.2-g and a volume of 2.56-cm3 be Iron?
Explain.
28. If 1.35-g of aluminum occupies
0.500 cm3, what is the density of
Aluminum?
26. The density of Gold is 19.3-g/cm3 .
What is the mass of 11.3-cm3 of Gold?
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